title: Hypoxemia and arrhythmia during daily activities and six-minute walk test in fibrotic interstitial lung diseases.
abstract: We performed 24-hr monitoring of pulse oximetric saturation (SpO(2)) with ECG and six-minute walk test (6MWT) in 19 patients with fibrotic interstitial lung diseases (ILD) to investigate; 1) The frequency and severity of hypoxemia and dysrhythmia during daily activities and 6MWT, 2) safety of 6MWT, and 3) the parameters of 6MWT which can replace 24-hr continuous monitoring of SpO(2) to predict hypoxemia during daily activities. All patients experienced waking hour hypoxemia, and eight of nineteen patients spent > 10% of waking hours in hypoxemic state. Most patients experienced frequent arrhythmia, mostly atrial premature contractions (APCs) and ventricular premature contractions (VPCs). There were significant correlation between the variables of 6MWT and hypoxemia during daily activities. All of the patients who desaturated below 80% before 300 meters spent more than 10% of waking hour in hypoxemia (P = 0.018). In contrast to waking hour hypoxemia, SpO(2) did not drop significantly during sleep except in the patients whose daytime resting SpO(2) was already low. In conclusion, patients with fibrotic ILD showed significant period of hypoxemia during daily activities and frequent VPCs and APCs. Six-minute walk test is a useful surrogate marker of waking hour hypoxemia and seems to be safe without continuous monitoring of SpO(2).
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan, College of Medicine, 86 Asanbyeongwon-gil, Seoul, Korea.
authors.forename: Jeong Hyun
authors.initials: JH
authors.lastname: Park
authors.forename: Yangjin
authors.initials: Y
authors.lastname: Jegal
authors.forename: Tae Sun
authors.initials: TS
authors.lastname: Shim
authors.forename: Chae-Man
authors.initials: CM
authors.lastname: Lim
authors.forename: Sang Do
authors.initials: SD
authors.lastname: Lee
authors.forename: Younsuck
authors.initials: Y
authors.lastname: Koh
authors.forename: Woo Sung
authors.initials: WS
authors.lastname: Kim
authors.forename: Won Dong
authors.initials: WD
authors.lastname: Kim
authors.forename: Roland
authors.initials: R
authors.lastname: du Bois
authors.forename: Kyung-Hyun
authors.initials: KH
authors.lastname: Do
authors.forename: Dong Soon
authors.initials: DS
authors.lastname: Kim
mesh_terms: D000203:Activities of Daily Living; D000368:Aged; D001145:Arrhythmias, Cardiac / Q000503:physiopathology*; D004417:Dyspnea / Q000503:physiopathology; D015716:Electrocardiography, Ambulatory; D005080:Exercise Test; D017079:Exercise Tolerance; D005260:Female; D006801:Humans; D000860:Hypoxia / Q000503:physiopathology*; D017563:Lung Diseases, Interstitial / Q000503:physiopathology*; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D010092:Oximetry; D012129:Respiratory Function Tests; D012890:Sleep; D016138:Walking